On evenings and weekends with beautiful weather, I tend to jump on my old-timer scooter and ride the winding roads in the neighbourhood. The scooter is from 1962, and my father used to drive it to work in the sixties. It is still rolling along due to its high build quality and my ongoing good maintenance.
You might have read that the oldest operational Kipp & Zonen pyranometer we found is located in Freiburg (Germany) and 46 years old. Like my scooter, it is still operational due to its build quality and good maintenance! You have to clean the dome, ideally at least every 2 weeks (or as soon as it gets dirty) and at the same time check the levelling and inspect the desiccant colour (and change it when required). With many of our recent instruments you don’t even need to check the desiccant, it is sealed inside.
Part of pyranometer maintenance – and luckily not part of old-timer scooter maintenance – is regular re-calibration. Under the influence of solar radiation, mostly the UV light, the sensitivity might have changed slowly over time.